Catabolic Properties of Microdissected Human Endosteal Bone Lining Cells

Bone lining cells cover >80% of endosteal surfaces of human cancellous bone. Current research assigns to them a dual role: (1) as a biological membrane regulating exchange of substrates between the bone fluid compartment and the extracellular fluid of bone marrow and (2) as a signaling link between the osteocytic network as mechanical receptor and the osteoclastic cell pool for local induction of bone resorption. Furthermore, a catabolic role has been considered. We therefore examined the presence of matrix-metalloproteinases (MMPs) and their physiological tissue inhibitors (TIMPs) as putative proteolytic elements. Firstly, human cancellous bone from 60 patients was examined by immunofluorescence with antibodies against MMPs and TIMPs. Secondly, we applied laser-assisted microdissection (LMD) to isolate bone lining cells from frozen sections of human trabecular bone. mRNA analysis was performed using a single-cell PCR protocol. Three laser microdissection systems were tested: the new generation of Leica LMD and P.A.L.M. laser pressure catapulting (LPC) were compared to P.A.L.M. laser microdissection and micromanipulation (LMM). In a few pooled cell profiles, mRNA of MMP13, MMP14, TIMP1, and CBFA-1 was clearly detected. By immunofluorescence MMP13 and -14 as well as TIMP1 and -2 were strongly present in lining cells, while MMP2, TIMP3, and TIMP4 showed weak or negative signals. Although the functional impact of these enzymatic components remains open, there is additional evidence for a catabolic function of lining cells. The new diode-laser microdissection with LMD and LPC proved to be especially suitable to gain new insights into the properties of bone lining cells.     

Altersabh?ngigkeit der Sekund?rdentinanlagerung im Pulpencavum

This study examined whether increasing apposition of secondary dentin in the pulp cavity of healthy and vital teeth observable throughout life could represent a suitable criterion for forensic odontological age estimation in juveniles, adolescents and young adults. For this purpose 1,299 conventional orthopantomograms of 650 female and 649 male Germans in the age group between 15 and 40 years were studied. The scale of secondary dentin apposition of the mandibular premolars was determined on the basis of a 3-stage classification system. A pulp horn reaching as far as the crown equator (stage 1) appeared at a minimum age of 15.12–18.01 years depending on sex and the tooth studied. A pulp horn located between the crown equator and the cementoenamel junction as a result of advanced secondary dentin apposition (stage 2) occurred at a minimum age of 19.61–33.08 years depending on sex and the tooth studied. Thus the evaluation of secondary dentin apposition can be helpful in establishing completion of both 14 years and 18 years of age.     

Animal models for neonatal diseases in humans

The development of vaccines for infants and young children requires the use of animal models at various stages of preclinical development. Animal models are being used to assess the quantity and quality of the immune response, onset and duration of the response, induction of systemic versus local immunity, protection against challenge infection for the assessment of vaccine efficacy, as well as safety and toxicity of the vaccine formulation itself. A variety of animal models are available, each with its own specific advantages and disadvantages. Here, we review the most common animal models for preclinical vaccine development for human infants.     

Functional genomic screen of human stem cell differentiation reveals pathways involved in neurodevelopment and neurodegeneration

Human embryonic stem cells (hESCs) can be induced and differentiated to form a relatively homogeneous population of neuronal precursors in vitro. We have used this system to screen for genes necessary for neural lineage development by using a pooled human short hairpin RNA (shRNA) library screen and massively parallel sequencing. We confirmed known genes and identified several unpredicted genes with interrelated functions that were specifically required for the formation or survival of neuronal progenitor cells without interfering with the self-renewal capacity of undifferentiated hESCs. Among these are several genes that have been implicated in various neurodevelopmental disorders (i.e., brain malformations, mental retardation, and autism). Unexpectedly, a set of genes mutated in late-onset neurodegenerative disorders and with roles in the formation of RNA granules were also found to interfere with neuronal progenitor cell formation, suggesting their functional relevance in early neurogenesis. This study advances the feasibility and utility of using pooled shRNA libraries in combination with next-generation sequencing for a high-throughput, unbiased functional genomic screen. Our approach can also be used with patient-specific human-induced pluripotent stem cell-derived neural models to obtain unparalleled insights into developmental and degenerative processes in neurological or neuropsychiatric disorders with monogenic or complex inheritance.     

Cross‐sector emergency planning for water supply utilities and healthcare facilities

The purpose of this article is to outline the criticality of water supply in sustained operations of healthcare facilities, particularly during community emergencies, and to advocate for enhanced cross‐sector support from the water utilities in meeting this need. Information and ideas presented here were developed in the course of a regional project sponsored by the Metropolitan Washington Council of Governments (MWCOG) for development of emergency water supply operations plans for critical water uses in the Washington, DC, area.     

Trends in ophthalmology journals: a five-year bibliometric analysis (2009-2013)

AIM: To explore the trends in the ophthalmic literature over a 5-year period in relation to country, research expenditure and demographics. METHODS: Articles published between 2009 and 2013 by the 20highest-contributing countries in the 20 top-ranked ophthalmology journals were identified by their country of affiliation. The number of articles published and mean impact factor were measured per country for each year and trends explored using regression analysis with 5-year and 10-year forecasts calculated. Data on research expenditure was collected and tested for correlation with the number of articles and mean impact factor. RESULTS: The analysis included 19 338 articles. The USA, UK and Europe accounted for 60.2% of articles published, with the USA contributing 7388 articles (34.0%). The USA also demonstrated the highest mean impact factor (3.5). Research expenditure was significantly correlated with both research output (r=0.86, P<0.001) and scholarly impact (r=0.42, P<0.001). China (P<0.01), Korea (P<0.01) and India (P<0.02) demonstrated a significant growth in research output over the study period. The research contribution of these three countries combined is forecasted to overtake that of Europe within ten years, with China expected to be the second-largest contributor within five years. These countries were also among those demonstrating the greatest growth in research expenditure. CONCLUSION: While the USA and European countries are major contributors of ophthalmic research, the productivity of some Asian countries is growing impressively. The contribution of China, Korea and India is forecasted to outweigh that of Europe by 2023. Research expenditure is highly correlated with research productivity and these trends reflect the differing economic priorities across the world.     

Patient Characteristics as Indicator for Care Dependence after Hip Fracture: A Retrospective Cohort Study Using Health Insurance Claims Data From Germany

Objectives

Hip fractures are common consequences of falls in older adults and, among other negative health outcomes, often lead to care dependence in the long term. Until 2016, the German long-term care insurance classified care recipients according to a standardized classification system consisting of 3 care levels. It was based on required assistance in performing activities of daily living and assessed by a qualified physician or nurse. Thus, care level reflects the degree of care dependence. The aim of this study was to determine relevant patient characteristics, which are related to the likelihood of increasing care dependence in terms of worsening care level after hip fracture.

HLA-haploidentical blood progenitor cell transplantation in osteopetrosis

Infantile osteopetrosis (OP) carries an extremely poor prognosis unless treated early by hematopoietic stem cell transplantation. We explored the use of purified blood progenitor cells from HLA-haploidentical parents in 7 patients lacking suitable matched donors. Blood progenitor cells were purified by positive selection and by additional T-cell depletion using rosette formation. For conditioning, patients received busulfan, thiotepa, and either cyclophosphamide (5 patients) or fludarabine (2 patients). Stable donor engraftment developed in 6 of 7 patients. Graft-versus-host disease was not observed. Three of the 7 patients had no major complications and 4 of 7 had both veno-occlusive disease and respiratory failure. Five of 7 patients survive with complete cure of OP at a median of 4 years. Patients with OP lacking HLA-matched donors can be successfully treated by transplantation of purified blood progenitor cells from HLA-haploidentical donors.     

Relationship between body fat mass,carbohydrate tolerance and iri response during glucose infusion in subjects with early diabetes

Summary We have studied the interrelationship of total body fat mass, carbohydrate tolerance and IRI response in 17 non-obese and obese subjects, who were suspected of having early diabetes. We carried out an i.v. glucose infusion test consisting of a priming injection of 0.33 g/kg followed by constant glucose infusion of 12 mg/kg/min in all persons. Total body fat mass was estimated by the tritium dilution method. There was a positive correlation of body fat mass, fasting glucose concentration and blood glucose concentration at 150 min as well as a strong correlation between body fat mass and BG area 60–120 min as parameters of carbohydrate tolerance in all subjects, i.e. the degree of carbohydrate intolerance was directly related to the quantity of total body fat mass. A similar correlation was found when the non-obese and obese groups were analyzed separately. In neither group did total body fat mass correlate with parameters of IRI response. In obese subjects with pathological carbohydrate tolerance, however, a positive correlation of basal IRI concentration and total body fat mass was found. Furthermore, a close relation between basal IRI level and parameters of carbohydrate tolerance could be demonstrated in obese subjects. The present study failed to demonstrate any correlation of parameters of carbohydrate tolerance and glucose-induced IRI response in either group. Thus, the significant relationship between body fat mass and degree of carbohydrate intolerance indicates that total body fat mass plays an important role in the disturbance of blood glucose homeostasis in early diabetes with and without obesity. Investigation performed within the medical research project ‘Diabetes mellitus and disturbances of lipid metabolism’, Ministry of Health, GDR.